Various types of remote control systems are available for use with garage door openers, home automation systems, vehicle locking systems, and the like. A common element found in many remote control systems is the use of an encoded signal transmitted from a transmitter to a remote receiver. The receiver receives the encoded signal, compares the code contained within the signal with a stored code or codes, and activates the remotely controlled device if the received code matches the stored code. If an invalid code is received by the receiver, the remotely controlled device is not activated.
Various systems have been developed to ensure that the encoded signal transmitted by the transmitter is accepted by the receiver. Early systems used a series of switches contained in both the receiver and the transmitter which could be set to any pattern desired by the user. Typically, a series of two-position or three-position slide switches or rocker switches are contained in both the transmitter and the receiver. The user of the remote control system sets the pattern of the switches in both the transmitter and the receiver to be identical. If multiple transmitters are used with a single receiver, the switches in each transmitter are set to the same pattern; i.e., the pattern set in the receiver.
Remote control systems which require the setting of various switches are somewhat tedious, especially for a user who is not mechanically inclined. If the transmitter and receiver are purchased as a single unit, the switches in both devices may be set to match one another at the factory. However, if the units are purchased separately, or if an additional or replacement transmitter is purchased at a later date, the user must set the switches before the system can be used. This requires first determining the switch settings in the existing receiver. Next, the new or replacement transmitter is partially disassembled to access the switches contained within the transmitter. The switches in the transmitter are then set to match those of the receiver, and the transmitter is reassembled.
Another type of remote control system uses a "smart" receiver design which is capable of learning a code contained in a transmitter. Typically, these smart receivers include a memory device capable of storing several different valid codes, thereby allowing use of several different transmitters, each having a different code. Transmitters used with smart systems do not use switches to set the transmitted code, but instead use a permanent electronic serial number. This electronic serial number is unique to each transmitter and cannot be changed by the user.
Smart systems operate by first placing the receiver in a "learn" mode wherein it stores any encoded signal received from a transmitter. Once the receiver is switched to the learn mode, activating a transmitter to be used with the receiver stores that transmitter's code in the receiver's memory. The transmitter is activated in the usual manner, such as by pressing the activation switch. Since the transmitter does not use switches to generate the code, a minimal amount of user interaction is required. User interaction is usually limited to the movement of a single switch on the receiver between a "learn" position and an "operate" position, and activation of the transmitter.
Remote control systems for operating a garage door typically consist of a receiver unit permanently mounted in the garage, adjacent the motor-driven garage door opener. One or more remote transmitters are located in the vehicles which will require access to the particular garage door. Since the transmitter units are small portable devices located within the car, they are susceptible to damage, theft, or misplacement. Therefore, it is common for the receiver to outlive or outlast the portable transmitter. When a portable transmitter is replaced, the user must know which type of receiver unit is located in the garage, and purchase the appropriate transmitter for that receiver system. Furthermore, the merchant who sells remote control systems must maintain a stock of transmitters capable of operating the older, switch-controlled coding systems as well as a stock of newer, smart transmitter devices. Therefore, the merchant must either maintain a supply of two different portable transmitters or neglect customers who own older systems, and carry only the newer smart transmitters.
Similar problems exist with the use of code key transmitters. A code key transmitter is typically a small housing mounted exteriorly of the garage which includes a keypad providing numeric input to a controller or microprocessor. A PIN code is selected by the user and stored in a memory coupled to the microprocessor to validate an open/close signal from a user. Such code key devices transmit a coded signal to a receiver located within the garage after a PIN number input via the keypad has been validated as matching the previously stored PIN number.
The codes in such code key devices have been provided by dip switches or electronic I.D. codes stored in the memory. Such codes, as with remote transmitters, must be programmed to match the code in the receiver. In addition, some code key devices are programmable to match the receiver code. In such devices, the user, when in a program mode, hits the switch numbers from 0 to 9 which are to be set to "1" state. The remaining, unprogrammed switch numbers at a "0" state. This enables the code key device to transmit the serial signal containing the binary code which matches the code in the receiver.
Thus, as with remote transmitters, a merchant must either maintain a supply of two different types of code key devices or neglect customers who own older systems which use dip switches.